This invention relates to a method and apparatus for transferring bulk foliage from one container to another and, more particularly, for transferring mechanically harvested green tobacco leaves from a collection trailer, which is carried on the mechanical harvester, into a bulk curing container that can be inserted into a curing barn.
The continuing emphasis of mechanical harvesting of the tobacco leaf which began in the 1960'with the first commercially successful mechanical tobacco harvester has produced the need to devise other green leaf handling concepts. Initially, tobacco was harvested by hand and each leaf was retained in proper alignment from the harvesting operation into the curing barn. This was done to insure that the leaf would cure properly.
Although the mechanical harvester has improved the priming of the tobacco plants and reduced the labor required in the field, a bottleneck occurs around the curing barn because the transfer of the leaves into the curing racks is generally still done by hand, thereby, limiting the advantages of using the mechanical harvester.
In order to take full advantage of the mechanical harvester, attempts have been made to eliminate the manual transfer of leaves from the collection trailer to the curing rack. The basic approach to this problem has been to utilize the collection container as the curing container. U.S. Pat. Nos. 3,834,137 and 3,948,553 illustrate this concept. It has been found that two problems are produced by utilizing the collection container as the curing container. The first problem is simply weight. The capacity of the tobacco harvester is now between 4,000 and 8,000 pounds per hour and a single trailer load of tobacco is about 3,000 pounds. If the collection container is used as the curing container, it must be sturdily constructed because of the increased handling. Therefore, an additional amount of weight is added to the tobacco harvester in the field because of the sturdy trailer construction. It can easily be seen that, by adding the weight of an attendant to the weight of the tobacco leaves and the trailer, the field load on the rear of the mechanical harvester can easily be between 4,000 and 5,000 pounds. Such a large weight makes it difficult to harvest the fields when they are wet. Thus, any reduction in the weight of the harvester is important.
The second problem, which is probably the most significant, is the density of the leaves in the collection trailer. In many instances, tobacco fields are located from one half to several miles from the curing barn area and the routes which the trailer must travel are invariably rough. The harvested leaves are constantly being bounced up and down, producing a packing effect so that the density of the bottom leaves is much greater than the top leaves. If a collection trailer is used as the curing container and this uneven density situation is allowed to persist, there will be an uneven curing of the leaves during the curing process because the hot air streams will seek the path of least resistance and will pass through the less dense leaves.
Even with the attendant on the harvester, this problem cannot be overcome because the problem is not produced until the collection trailer is pulled between the field and the curing area. The only way known at the present time to overcome the problem is to manually remove the leaves from the trailer and either utilize the rack system illustrated in U.S. Pat. No. 3,110,326 or a large bulk curing container which is known in the art.